Described are methods for intraoperative imaging of anatomical structures using fluorescent compounds, e.g., compounds that fluoresce in the invisible light (IL) region of the spectrum, i.e., above 670 nm. An exemplary compound is methylene blue.
FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
 This invention was made with Government support under Grant No. R01-CA-115296 awarded by the National Institutes of Health and Grant No. DEFG02-01ER63188 awarded by the Department of Energy. The Government has certain rights in the invention.